The present invention relates generally to a powder paint transfer assembly, and more particularly to a powder paint recirculation block assembly for use in the powder paint transfer assembly.
Paint application systems, such as those for painting vehicle bodies, may include recirculation valve assemblies that selectively direct the paint either to a paint applicator or back to the supply of paint. Some of these paint application systems are used specifically for the application of powder paint to the vehicle bodies. A problem that has arisen in the paint application systems for powder paint is that the recirculation valve assemblies include flow direction changes at relatively large angles. These large angles of flow direction change do not work well with powder paint. This is because the large angles of flow direction change are believed to cause impact fusion to occur—impact fusion is believed to be caused when powder paint particles impact together causing heat, which then fuses the particles together. The fused powder paint, then, eventually closes off the flow passages, requiring the painting operations to stop while eliminating these clogs.
Another problem that has arisen in the paint application systems for powder paint is that some of the recirculation valve assemblies include pinch valves, and the pinch valves do not have serviceable components. As a result, when the assembly is cleaned (after painting) the membranes of the pinch rubbers wear, which eventually leads to failure of the rubbers. Since the pinch valves do not have individual serviceable components, the entire valve assembly must be replaced when the membranes are worn out. This results in much higher maintenance cost than is desirable.
Thus, it is desirable to have a powder paint recirculation block assembly for use in a powder paint transfer assembly that overcomes the drawbacks of the prior art.